With two skinned knees, short hair ""chopped off for the summer by Albert the barber"" and a male best friend, Rosie, the heroine of Giff's inviting new Ballet Slippers series, doesn't seem a likely candidate for ballet lessons. But the plucky narrator has always wanted to fill the satin slippers of her late grandmother, a ballerina. When a ballet school opens in town, Rosie is sure her big chance has arrived, until she realizes she's missed the sign-up and the class is filled. To make matters worse, she and her best friend are feuding--though she's not sure what the tiff is all about. With characteristic agility and wit, Giff rights all that's wrong, although (in the swiftly moving plot's single snag) it is not entirely clear why Rosie is suddenly able to join ballet class after she sneaks into the studio and chats with the piano player. Readers will be immediately drawn to Rosie's resilience and humor. At one point, she tries to cover up a faux pas in class: ""I kept smiling. I made believe I was way ahead of everyone else instead of miles behind.... Everyone would think I had learned a special step from my famous ballerina grandmother."" Readers will also cotton to Giff's encouraging message about the power of determination. The second installment, Rosie's Nutcracker Dreams, is also due this month; Starring Rose is due next February. Ages 7-11. (Oct.)